In recent times, adverse publicity has affected the sales of hormone replacement therapies and the perception of women as to whether or not HRTs should be taken. While a number of brands are available, those from Wyeth are the market leaders. Previous studies by our group have shown an advantage of Premarin, a natural conjugated equine estrogen, in fostering recovery of the Lactobacillus flora in the vagina. These organisms have been shown to help protect the host from urinary and vaginal infections. In the present proposal, we aim to further examine the beneficial effects of Premarin through the use of a human genome array technology.